Sequential brain scanning as an adjunctive scanning procedure

Sequential brain scans were performed at various time intervals of up to four hours after injection of 99mTc pertechnetate in 108 patients who had previously undergone "routine" one-hour brain scans which were considered normal or equivocal. Forty-six patients were proved to have a discrete morphologic brain lesion. Pathologic processes were demonstrated by the sequential scanning technique in all but 6 cases. In nearly a third of these 46 patients (28%), careful observation of the progressive and subtle changes in radioactivity in the whole sequential scan series was necessary for detection of the lesions: they could not be appreciated on any single static scan when viewed independently.